Parachute



July 10, 1951 P. F. SMITH 2,559,804

PARACHUTE Filed Nov. 12, 1947 2 SheQts-Sheet 1 INVENTOR.

July 10, 1951 P. F. SMITH 2, 0

PARACHUTE Filed Nov. 12, 1947 2 Sh eet's-Sheet 2 Fly. 1 0

INVENTOR.

Patented July 10, 1951 UNITED STATES ATENT OFFICE PARACHUTE 'PrevostF. Smith, San Diego, Calif. Appiiaai means 12, 1947, Serial No. 785,371

21 Claims. (Cl. 244 152) This inventionrelates to a parachute that ,aiitoma'tically.changes shape as the velocity decreases, for the purpose. of obtaining a low coefii- "cient of drag (Cd) at highspeed' and in the initially opened position and thena highcoeflicient Io'f drag (Cd) atlow speedas the object to be suppo'rted'by theparachute has been decelerated.

More particularly, experiments to date with one model'show that while'it will support a 50 pound weight at miles "per hourdescent, the pull at jl'0 5' miles per hour is approximately only 300 "p'oundsfwhere with a conventional'parachute it wean be about2500pouhds'. Thus at high speed,

as theparachute is first 'deployed and opens, its 'c fi t' f dra is only .15, but after decelerating the load to a safe low speed, the Cd becomes 1.2. "Further the parachute lends itself to change in adjustment so as to accomplish desired results with various loads and speeds, although the .above change in Cd remains about the same. For J example a 400 pound robot missile on the above mentioned model would have an estimated drag of 5000 pounds at 425 miles per hour, yet would safely descend at 42 miles per hour after decelerating.

shock load approaching 40,000 pounds.

The principal object of this invention is to produce a parachute that will be unable to exert a high drag at high speed.

Another object is for said parachute to produce a high drag at low speeds comparable to conventional standard parachute.

A third object is to eliminate oscillation particularly at high speed.

A conventional parachute giving the ..'same rate of descent would have an opening With these and other objects in view as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement of parts and portions, as will be hereinafter described in detail and particularly set forth in the appended claims, reference .-oe lerating a missile from very high speeds in which the fabric takes the shape of a lampshade (technically the frustrum of a cone) thereby relieving, all excess pressure since the .vent is almost as big as the mouth of the para- .chute. This shape can also be called a conical .,.parachute with a large vent.

2is a fragmentary side view of the same aiter -.the; sp eed. has decreased .to a m nimum matic control 2 thereby the vent is almost closed and the (id is very high. j Fig; 3 is a fragmentary side elevation view of a modification of this parachute shown decelerating a missile from very high speed in hichth e fabric takes the shape of a crownttherebyre moving unnecessary material andfurther reducing the Col at high speed. 1

Fig. 4 is an enlarged side view of the :panelson the crown parachute takenirom FiELB as'the vent is in the high speed'wide open position.

Fig. 5 is a side view of the same after the speed has decreased to a minimum thereby the vent is almost closed and the Cd is at its maximum. Fig.6 is an enlarged view of a section of the panels taken from Fig. 5 showing the panelsh ld together, closing the vent and causing the maximumCd. Fig. 7 is a fragmentaryv view of the lamps canopy w t a mod fica io o the au shownin the wide open high speed p siti n.

, Fi Sis a a men a V ew, o the sam lampshade canopy with the modified automatic control shown in the olo sed low speed,condi t ign."

Fig. 9 is a full size side view of the automatic control shown in Fig. 7 with one of the side covers removed showing the arrangement o'fjthe suspension webs and thelocking means while Fig 10 is an end view ,of the same without the suspension webs.

Similarcharacters of reference refer to simi'- lar parts and portions throughout the several views of both the simple and more complex illustrated variations of. the parachute.

' As shown in Fig. 1, the fabric is, formed as the frustum of a coneso that the diameter ofthe mouth. of the parachute is slightly larger than the vent. ,Also the proportions are such that the diameter is about. doublethe height. The fabric is suitably reinforced at the edge of both mouth and vent so thatthe outside suspension lines. 2, and the inside suspension lines 3 may be securely sewed thereto at suitable intervals consistent with the strength of the line andthe maximum design velocity load. The lines 2, are tied to a common ring 4, to which a cable 5, connects to the load 6., to be supported 6. .The inside lines}, whose lengths are preferably equal the radius of the mouth of the parachute, .tie to a common heavy line 1, that is in turn fastened to the top end of a length of elastic shock cord whose lower p end is tied to the ring 4 and whose length is sufficientto easily operate between the vent full-y opened aild losed positio i'Ifhns at gh speeds.

the air blast, in creating a large force against the vent of the parachute, extends the elastic 8, by means of the vent lines 3 and I. Then as the load 6 is decclerated, the elastic 8 retracts the vent down and inwards thereby trapping the air and producing a shape as shown in Fig. 2 that has about the same Cd as a standard conventional parachute. They have shown that the parachute illustrated in Fig. 1 is 100% stable with no oscillation at any speed.

Fig. 3 is a modification of the above design in which a further reduction in drag at high speed is obtained and also a reduction in the quantity of fabric used so that at low speeds, the Cd is as high or higher than that of a conventional parachute based upon an equal quantity of fabric. In this design, the shape is still a frustrum of a cone but the appearance is like a crown, as illustrated by the portion shown in Fig. 4. The skirt to which the lines 2 are attached is a portion of a cylinder la, whose height is about l/Gth the diameter. To this are sewed the longer base sides of a series of regular trapezoids lb, whose sizes are such to produce a shape similar to Fig. lin the open position and Fig. 2 in the closed position. In the upper reinforced corners of each trapezoid are inserted grommets 9, through which loops H), on the ends of the inside lines 3 are passed. These loops are of such a size that they fully permit the vent to open wide at high speed as in Fig. 4 and in combination with the lines 3 have a diameter about the same as the mouth of the parachute so that a very large ratio exists between the force pulling the vent closed and the force of the elastic 8. More specifically a very. small force from the elastic exerts a very strong force to close the vent. Thus as the velocity of the load decreases the peaks of the trapezoids are pulled together and down forming a regular parachute thereby effecting a high Cd to obtain a low rate of descent, as shown in Fig. 5 and in the enlarged portion of a top view Fig. 6.

The structure of the modified control means shown in Figs. 7, 8, 9 and consists of nonelastic means of automatically closing the parachute vent as the velocity is decreased and operates by a displacement of the inside lines 2 to the outside lines 3, caused by the greater tension of the outside lines than the inside lines when using the grommets spaced about the vent and loops on the ends of the inner suspension lines 2 as illustrated inFigs. 4 and 6. To facilitate such displacement of the lines, the outside suspension lines on opposite sides of the parachute are attached to two pieces of webbing whose lengths are about /6 the diameter of the parachute and whose other ends join and attach to the center line I so that in the wide open. position the webs are high on the inside of the parachute. The webs transfer their tension to the load to be supported through cables 5 and a braking device l2 that automatically prevents the said displacement of the lines until the velocity has decreased.

Referring to Figs. 9 and 10, this braking device consists of a cage with two vertical members [2a and H2) in which two axles l3 are horizontally disposed between, upon which are mounted two freely rotating resilient rollers l4 under which the webs l l are looped. A lower horizontally disposed pin l5, through the frame l2 and He holds the braking device to the load 6 through the cable 5. Other locking pins l6, are disposed above the rollers M with knurled faces so that the webbing is threaded between them and the rollers l4. Two other pins IT, with knurled faces.

are positioned just above the resilient rollers l4 so that as the parachute is first deployed at very high speeds in the vent fully open position, the drag pulls on the webs I I over the resilient rollers which are deflected against the pins l1 and also the webbing is jammed against the pins 16 thus effecting a positive lock to hold the parachute in that open position until the velocity has substantially decreased. Then the resilient rollers assume their normal shape and release from the pins l6 and I1 permitting the displacement of the webbing from the inside to the outside since in the fully opened position, tests have verified the design theory that the inside load on the line I is but a small fraction of the load on the outside lines and even as the displacement becomes complete at a low speed, the load on the inside line 1 is still only /5 of the total load. Thus there is always a positive differential of force to effect the displacement of the web so as to close the parachute vent. The ends of the web II are turned so as to act as stops in order to limit the travel over the rollers it between the two desired conditions of the parachute.

While I have shown and described the particular construction, combination and arrangement of parts and portions of the principal embodiment with two modifications of my invention, I do not wish to be limited to this particular construction, combination and arrangement of parts and portions in the principal embodiment and modification but do desire to include in the scope of my invention the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A conical parachute of the class described, suspension lines secured to the skirt of said canopy, inner suspension lines arranged in conjunction with the vent so that the tension on the outer suspension lines is substantially greater than that of the said inner lines, a cage attached to the load to be supported, an axle through said cage, a resilient roller adapted to freely rotate on said axle, a webbing secured to the ends of said inner and outer suspension lines and passing under said roller, stationary locking means adjacent said roller adapted to lock said roller against rotation when excess tension of the said webbing due to an excessive high speed deflects said resilient roller against said locking means thereby holding the vent open until deceleration has reduced the load thereby releasing said resilient roller from said locking means permitting the roller to rotate and the lines to be displaced pulling the vent down and inwards to effect a low rate of descent.

2.A conical parachute of the class described, suspension lines secured to the skirt and inner suspension lines arranged in conjunction with the vent of said canopy so that the tension'on the said outer suspension lines is substantially greater than that Of the said inner lines, a cage attached to the load to be supported, a roller adapted to freely rotate in said cage, a webbing secured to the ends of said inner and outer suspension lines and passing under said roller, stationary locking means adjacent said roller adapted to lock said roller against rotation due to excess tension of the said webbing at excessive high speed, thereby preventing movement of said webbing around said roller, thereby holding the;

vent lopenuntiliidecelerati'onhas:reduced:therload:

thereby "releasing: saiditlockin'gr; means:- to? permit; thesaidroller to rotate and :theilines J to iber'dise. placed, pulling the-vent down :and: inwards: to' ef -i fect alow rate :of descent;

, 3.." A conical p'arachutexofthe lclassudescribedi' suspension: lines secured to theflskirtioftisaid canopy; inner'tsuspension 1 lines arranged in :cons; junction with the vent so that'theitension onv the outer suspension'lines issubstantially greater than'thatlsof the said 'inner' lin'es,:.a"webbingtonz the ends of said inner and outer 'lines aloadz supportingroller'over thesaid'webbing so adapted: asz'to transfer the tension of said webbing' to the' loadnto be'supportedgmeans to lock 'said :rollere to'aprevent its rotation when the openingshock: load "of. said .parachuteexceedsi'a designedimaxisi mum;:thereby preventing movement ofsai'd webbing. over said roller to prevent the displacement 2 ofizthe :inside lines downwardslandtthe outside lines upwards thereby holding thesaid vent open: untilthe deceleration has reduced theload there-.1 by releasing said locking means permitting :said; displacement solthatthe vent ispulled down and; inwards trapping the airrto effect: a'low rate of descent.

4.: A.'conical parachute of the iclass' describedl suspension lines secured to the skirt of said canopy,'inner suspension lines :arranged'in conjunctionz' with the .vent so that the tension-onithe' outer suspension lines is substantially greater than that of the said inner lines, a webbing on I the ends of said inner and outer: linespadoad supporting roller over which said webbing is engaged to transfer the tension of said-webbing-tothe load-to be supported, whereby deployment of i the parachute: will cause the displacement of the said inner lines down and the said outercslines' up so: that the vent is pulled down and inwards" trapping the air' to effect a low'rate of descent;

6 therventidow-n 'andi ir 'i'wards alto trap thez l'air at? low speedi- 8i A -aparachutez of the class described "having a skirt which is-essentially the sectionof acylin de'r; a plurality of trapezoidal canop'y"portions whose basesi'are secured insequence about the upper periphery of :saiol skirt, a grommets in the upper portion of said trapezoidal canop'y'portions, inner suspension lines" with loops on the ends.

that: pass" through said 7 grommets and extend" der'ya plurality of trapezoidal canopy portionswhose bases are secured in sequence about the upper periphery of saidskirt, grommets in the uppen portion of said trapezoidal canopy portions; inner suspension lines with loops on the" ends that pass-through said grommets, means to-shorten the "length of the inner suspension lines'so as to all'o'wthe vent to fully open at high-speed while pulling the vent down and in wards to trap the air at low speeds.

lofA'parachute :of the class described. having a skirt which is essentially the section of a-cyl'in de'r, a plurality of trapezoidal canopy portions- I whose bas'es are secured in sequence about the 5. A conicaluparachute ofthe class describedsion lines,-means to change the-length of-"said suspension meansso as to allow the vent to fully open-at high speed while pulling theventdown and inwards to trap the air at low speed a 6. 'A'conical' parachute of'the class described,'

outer suspension lines secured to the skirt-of said canopy, a plurality of grommets placed in the vent of said canopy, inner suspension lines with loops on the upper :ends'that passthrough said grommets and extending-radially inwards of the vent, the length of theportion of the suspension lines extending inwards of the vent being approximately' equal to the radius of 'thevent, a suspension means attached to saidinner suspensionli'nes; means to change-the lengtli'of said suspension means so as to allow the vent to open wide at-high speed while pulling the-vent down and inwards to trap the air at low speed.

7. A conical parachute of the Class described,

outer suspension lines secured-to the skirt of said canopy, a plurality of grommets placed in thevent of said canopy, inner suspension lines with loops on the upper ends that pass through saidthe'uent' to open wideat high speed -while pulling 75 upper periphery of said skirt, grommets in the 35* upper portion of said trapezoidal canopy portions inner suspension linesthat-pass through said grommets, means to shortenthe length of the inner suspension-dines was to allow the vent to rful-ly open'at" high-speed while pulling-- the I vent dow'n andinwardstotrap the air at low' speeds 11. A parachute having a central-vent; sus penSion 'lines attached to-the skirt of said parachute, inn'er lines-attached 'to'the vent of said ;yparaohute a flexible suspension member con-- necting said suspensi'on lines and said inner lines; acage 'attached to a=lo'ad to-be supported, an axle-throughsa'id cage, a resilient roller adapted to be freely rotatable on said axle, a locking pin mounted fixed-in-the -ca'ge above said roller, the said suspension member movably engaging said-- roller to-tra'nsfer the load of the said parachute to' said age; guide --pins through said cage so positioned'as -to'hold the said suspension member f in close contact with said roller, whereby an ex cessive speedandload of 'said parachute causes the'said resilient roller to-oblate and jamb against said-locking pin and binding the said suspension member-between the said-roller and said guide pins, 'therebythe said roller ceases to rotate and the-"said suspension 1 member ceases to move around said rollers until deceleration-has reduced the load thereby releasing said resilient roller from sai'd' locking pins permitting the said susipen'sion m'ember: tomove around said roller and l pull the'ventdown to efiect a low rate" of descent; 12, Asiparachute of the class- 1 described; sus pension linesiattached' to'the skirt of said para-" chute, 'inner lines attached tothe ventof said' ,parachute; a flexible suspension member con necting 'said suspens'ion'lines and said inner lines} a cage attaohed to the 'loa-dto be supported, an 1 axle throu-g-h said-cage, a resilient roller adapted 5 to freel-y rotate on fsaidaxle; the said suspension rmembr movably engagingsaid' roiieraaaransrer the load of the said parachute to the said cage, locking means in connection with said roller so adapted as to prevent the rotation of the said roller when the load of the parachute is excessive, thereby preventing the movement of the said suspension member to pull the vent down until the speed and load has decreased.

13. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, an axle through said cage, a roller on said axle, the suspension member movably engaging said roller to transfer the load of the said parachute to the said cage, resilient locking means in connection with said roller so adapted as to prevent the rotation of said roller when the load of the parachute is excessive thereby preventing the movement of the said suspension member to pull the ventdown until the speed and load has decreased.

14. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, an automatically deflectable member extending through said cage, the said suspension member engaging said defiectable member to transfer the load of the said parachute to the said cage, guide pins through said cage to hold the said suspension member in close contact with said deflectable member, an excessive load of the parachute to deflect said defiectable member binding the said suspension member to prevent its movement around said defiectable member until deceleration reduces the load thereby releasing the said suspension member to move around said deflectable member, pulling the vent down to efiect a low rate of descent.

15. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, an automatically deflectable member extending through said cage, the said suspension member movably engaging said deflectable member to transfer the load of the parachute to said cage, guide pins in relation to said deflectable member so disposed that the said suspension member is held in close contact to said deflectable member, an excessive load of the parachute to deflect said deflectable member so that the said suspension member is retarded from moving around said deflectable member until deceleration reduces the load thereby releasing the said suspension member to move around the said defiectable member, pulling the vent down to effect a low rate of descent.

16. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, an automatically deflectable member mounted in said cage, the said suspension member engaging said deflectable member to transfer the load of the parachute to said cage, guide pins in relation to said deflectable member so disposed that the said suspension member is held in close contact to said deflectable member, whereby an excessive load of the parachute to deflect said deflectable member so that the said suspension member is retarded from moving relative to said deflectable member until deceleration reduces the load, thereby automatically releasing the said suspension member to move around the said deflectable member pulling the vent down to effect a low rate of descent.

17. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, a deflectable member mounted in said cage, the said suspension member engaging said deflectable member to transfer the load of the parachute to said cage, a guide pin mounted in said cage so disposed in relation to the said deflectable member that an excessive load of the parachute will bind the said suspension member preventing its movement around said deflectable member and past said guide pin until deceleration reduces the load thereby releasing the said suspension member to move around said deflectable member pulling down the vent to effect a low rate of descent.

18. A parachute of the class described, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, a defiectable member mounted in said cage, the said suspension member engaging said deflectable member to transfer the load of the parachute to said cage, locking means mounted in said cage so disposed in relation to said deflectable member and said suspension member that an excessive load of the parachute Will prevent the movement of said suspension member around said deflectable member until deceleration reduces the load, thereby releasing the said suspension member to move around said deflectable member, pulling the vent down to eflect a low rate of descent.

19. A parachute, suspension lines attached to the skirt of said parachute, inner lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, means including resilient locking means mounted in said cage for slideably retaining said suspension member, whereby an excess load causes said locking means to prevent the movement of said suspension member through said cage until the load has decreased.

20. A parachute, suspension lines attached to the vent of said parachute, a flexible suspension member connecting said suspension lines and said inner lines, a cage attached to the load to be supported, means including resilient locking means mounted in said cage to moveably suspend said suspension member in said cage, whereby an excess load causes said locking means to prevent the movement of said suspension member through said cage until the load has decreased.

21. In a parachute, a canopy having a central opening, inner lines connected to the canopy around the perimeter of said opening, said inner lines connected to a common flexible suspension means, said canopy having an outer skirt, outer lines connected to the perimeter of said skirt and secured to the opposite ends of said common flexible suspension means from said inner lines, an automatic friction operated locking load supdevice and said skirt to permit the angular 15 change and permit corresponding angular force components to act on said skirts for diametri- 10 cally extending the same and closing said opening.

PREVO'ST F. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,519,857 Lucas Dec. 16, 1924 2,235,657 Thornblad Mar. 18, 1941 2,308,797 Nasca Jan. 19, 1943 FOREIGN PATENTS Number Country Date 417,048 Germany July 23, 1921 

